Mechanical base



May 8, 1934- Dfs. GUsTlN ET AL 1,957,708

MECHANICAL BASE Filed April 24, 1931 l INVENTORS a5. G05 r//v A. B

SATES OFFICE MECHANICAL BASE Application April 24,

6 Claims.

This invention relates to electrical devices such as incandescentelectric lamps and relates more particularly to an improved base portiontherefor.

5 In the manufacture of certain electrical devices such as incandescentelectric lamps it is practice to provide the lamp with the base in theform of a metallic shell, or cap having one end open to receive a glassbulb. Usually the shells l or caps are threaded and are provided with acentral contact supported in the bottom of the shell by an insulativering. The shells, however, may be plain and provided with bayonet pinsor they may have entirely smooth surfaces as when l used as a base for alamp to be adjusted in another portion or socket, when the lamp is ofsuch character that the lament is to be positioned in definite relationto the base portion in lamps termed precision lamps.

$0 The usual type of lamp base is, however, comprised of a threadedmetallic shell which is secured to a lamp bulb neck by means of asuitable adhesive material which cements the bulb and base together. Theuse of a cementitious maa5 terial to attach the base to the bulb isextensively used in the practice of making incandescent lamps andobviously necessitates relatively expensive operations and since it isnecessary to bake the adhesive material to set or dehydrate it 3o theoperation of passing the bulbs and bases through a heating oven is alsoinvolved.

It is an object of the present invention to provide an incandescent lampbulb having the base attached thereto in a firm and practical mannerwithout the use of an intermediate cementitious material.

Another object of the invention is to provide a base mechanicallysecured to a bulb neck.

Anotherobject of the invention is to provide a 4@ base for the bulb ofan electrical device which may include a plurality of elements operatingto mechanically grip the base and cooperating with each other to retainthe base relatively immovable on the bulb neck.

It has heretofore been proposed to mechanically apply a base to a bulb,as for example, Patent Number 1,813,572 issued July '7, 1931, for Lampbase is assigned to the assignee of the present invention, a structureis shown wherein an angular collar is provided to grip the bulb neck anda metallic shell embraces the collar thereby holding it in place, thecollar and the shell being securely connected to provide a mechanicallyattached base.

'Ihe present invention utilizes a construction 1931, Serial No. 532,394

wherein a collar is initially attached to a bulb vneck by means ofindentations in the collar which indentations register or conform inshape with and are disposed in dimples or depressions in the bulb neck.The collar is in the form of a split ring or collar serving as aretainer band and a cylindrical metallic base shell is so disposed aboutthe collar as to rmly press the indentations into the depressions of thebulb neck. When so positioned the portions of the surface of the shellabove the indentations of the collar are deformed by spinning or areotherwise pressed inwardly to provide indentations in the shell to t andfully occupy the indentations in the collar.

It has been found that in order to practice the formation ofindentations in the shell, it is preferable to provide a perforationwhich subsequently constitutes the center of each of the indentations inthe shell.

This perforation facilitates the spinning operation allowing the metalto. flow or expand so that the indentations formed in the shell may bermly pressed i-nto the concave portions of the indentations of thecollar.

By this method the outer shell is secured to the collar in such mannerthat all lost motion is prevented by reason of the exact fit attained asa result of the disposition of portions of the shell in firm contactwith the indentations of the collar and since by this method it ispossible to cause portions of the metal of the shell to firmly engagethe entire concave surfaces of the collar, the collar will not only beforced tightly into position for engaging the bulb neck but the metalpressed from the shell will so completely occupy the concave depressionsin the collar that no appreciable or detrimental relative movementbetween the collar and shell or the collar and bulb will be possible.

This feature is of extreme importance in connection with mechanicallybased lamps since it will be appreciated that ordinarily when connectinga lamp base to a bulb neck it is difficult owing to physicalirregularities to provide a structure wherein the several componentparts fit with such degree of accuracy as to avoid slight relativemovement particularly where the parts are shaped separately and thenfitted, whereby slight differences in dimensions often result inlooseness between the parts when they are assembled. Slight movement ofthe cooperating elements which secure a base to a bulb may not besufficient to make the device inoperative but in the manufacture ofincandescent lamps where a rigid standard of manufacture is called forand particularly in an electrical device which must be made in largequantities and handled by inexperienced customers, any play in the partsor any looseness which might eventually cause the connected leading inconductors to separate, offers disadvantages which the manufacturerseeks to avoid.

Furthermore the mechanical base must be of such construction as to bereadily assembled and attachable to the base in such manner as tosuccessfully compete with the cemented base both in cost of therespective parts and in the consumption of time necessary to completethe assembly operation.

The present construction for mechanically attaching a base of a lampbulb will be more clearly understood from the following descriptiontogether with the accompanying drawing, in which Fig. 1 is a side viewof an ordinary incandescent electric lamp having a base attached theretoin accordance with the present invention.

Fig. 2 is an enlarged vertical cross sectional view of a bulb neckshowing the present mechanical base applied thereto.

Fig. 3 is an enlarged view taken on lines III-III in Fig. 2 and Fig. 4is a view showing the bulb neck, collar and base in perspective andseparated prior to assembly.

Although the present invention may be applied to various types ofelectrical devices employing a bulb it is shown and described inconnection with an incandescent electric lamp comprising a bulb 10having a lament 1l mounted on support wires l2 projecting from an arbor13 extending from a flare tube 14 which may be sealed to the bulb in theusual manner. Lead wires 14 and 15' are connected to the terminals ofthe iilament and extend downwardly into the base.

The bulb 10 is provided with a neck portion 15 which may be shaped byheating to provide cylindrical surfaces 16 and 17 and a shoulder 18. Thesurface 17 is provided with a plurality of dimples or depressions 19preferably three depressions are provided in equal space relation.

The base assembly to be attached to the bulb neck may comprise a splitcollar 21 and a metallic shell 22. The shell 22 as shown is providedwith the usual threads 23 and a central contact 24 which is insulatedfrom the shell by the usual .glass web 25.

Although the shell illustrated is provided with threads it will beunderstood that it may be of plain cylindrical form as for example whenused as a bayonet type of base or as part of the structure employed inmaking certain types of precision lamps. The collar or retainer band 21may be shaped -with cylindrical surfaces 26 and 27 of differentdiametrical dimensions to provide a seat 28 and the dimensions of theinterior cylindrical surfaces maybe such as to fit the surfaces 16 and17 of the formed bulb neck with the seat 28 engaged with the shoulder 18when assembled. The surface 27 of the collar is provided withindentations 29 in spaced relation and of a number equal -to thedepressions 19 so that when the collar is in place upon the bulb neckthe depressions will receive the convex portions of the depressions 29.The collar 27 being split at 31 is arranged to tensionally engage thebulb neck and hold the indentations 29 firmly in the depressions 19.When the collar 21 is so positioned the metallic shell 22 is moved tosurround the collar and is of such dimensions as to snugly flt the same,

The shell 22 is provided with three apertures or perforations 32arranged to register with the indentations 29 so as to position one ofthe perforations over .each of the indentations.

The metal around the perforations is then depressed inwardly by forcingwith a suitable tool or by spinning so that the entire inner surface 33of the deformed portions of tlie shell are disposed in rm contact withthe surfaces of the depressions 19.

As clearly shown in Fig. 3 the foregoing method makes it possible tosecure the shell to the collar in such manner as to prevent any play orlost motion and the formation of depressions 34 resulting from thespinning operation causes the several layersof metallic materialcomprising the shell and the collar to intimately engage each other andat the same time the collar is firmly secured to the bulb neck.

Although the perforations 32 are desirable and facilitate the formationof the depressions 34 it is to be understood that these perforations maybe dispensed with where the metal is soft or suiiiciently malleable tobe distorted by a forming tool applied to the outer surface of themetallic shell. The perforations, however, allow for the expansion ofthe metal as it is distorted and in practice it has been found thatthese perforations make it possible to obtain the desired intimaterelation between the depressions in the shell and the indentations inthe collar. As illustrated the lead wire 14 may be soldered or otherwisesecured to the contact 24 and the lead wire 15 may be disposed in anotch 30 in the edge of the base and may be soldered or otherwisesecured at 35 to 110 the shell 22. I

For the purpose of allowing for the thickness of the lead wire 15 thebulb neck may be formed with a slot 36 to receive a portion of the leadwire 15' so that the collar 21 will fit the formed neck 115 and enclosea portion of the said lead wire between the bulb neck and the shell.

In making a base in accordance with the present invention forapplication to the bulb neck of the usual standard incandescent lamp, itis desirable to first shape the bulb neck byrst directing fires againstthe neck portion disposed adjacent to the flange of the iiare tube insuch manner that the bulb neck and flare are sealed without thinning theglass above the point of consolidation.

The' -method of so forming the neck during sealing-in is clearly shownin copending application Serial No. 417,106 filed December 28, 1929 byD. S. Gustin for Method of sealing in, which application is assigned tothe assignee of the pres- 1m ent invention.

By this method a relatively large mass of glass is left in the neckafter the waste portion or cullet is cut off. The neck is then enclosedin a mold and air under pressure is introduced into the bulb to forcethe plastic glass against the mold so that it will take the requiredshape. The mold may then be removed and annealing fires applied to themolded portion to remove strains.

The cullet which is still connected by a thin wall of glass to themolded portion is then cut off and a further annealing operation isperformed.

The present invention provides a simple and practical method ofmechanically basing a lamp wherein the several parts may be readilyassembled and secured with the necessary degree of accuracy to provide abase relatively free from looseness and having the ruggedness necessaryfor a device of the present character.

,Although a preferred embodiment of the invention is shown and describedherein, it is to be understood that modifications may be made thereinwithout departing from the spirit and scope of the invention as setforth in the appended claims.

What is claimed is:

l. An electrical device comprising a bulb having a plurality ofindentations in the neck thereof, a band surrounding said neck, raisedbosses on said band engageable with said indentations to secure saidband to said neck and a base having bosses disposed in nested relationwith the bosses on said band.

2. An incandescent electric lamp comprising a bulb having lead wiresextending therefrom, the neck portion of said bulb having a plurality ofdepressions, a resilient band fitted to said neck portion, a pluralityof inwardly projecting cupshaped bosses formed from the wall of saidband and disposed in said depressions, a shell having a contactconnected to a lead wire, a portion of said shell being arranged to tover said band, the inside diameter of said portion being slightlygreater than the outside diameter of the band when the bosses thereofare firmly disposed in said depressions, said shell having inwardlyprojecting portions formed to nest in the concave surfaces of saidcup-shaped bosses.

3. An electrical vacuum device comprising a bulb having a neck portionformed with a plurality of depressions, a split band surrounding saidneck, indentations on said band and arranged for disposition in saiddepressions, a metallic shell contact member for said device, said shellhaving an inside diameter slightly greater than the outside diameter ofsaid band when the band is disposed with the indentations thereof in rmcontact with the surfaces of said depressions, said shell havingportions pressed into' intimate contact with the surfaces of saidindentations to secure the shell and band to said bulb neck.

4. An electrical vacuum device comprising a bulb having a cylindricalneck portion, said neck portion having al plurality of depressionsformed in the surface thereof, a retainer band surrounding said neck,said band having indentations to enter said depressions, a metallicshell Contact member for said device, said shell having a portionsurrounding said retainer band and of slightly greater internal diameterthan the outside diameter of said band when enclosed by said shellportion, said shell having portions formed to provide surfaces to pressagainst the surfaces of said indentations to firmly hold the band andshell against relative movement on said neck portion. 5. An electricalvacuum device comprising a vitreous container having a cylindrical neckportion, said neck portion having depressions formed in the surfacethereof, a retainer band surrounding said neck portion, a metallic shellcontact member having a portion surrounding said band and of an internaldiameter slightly greater than the external diameter of said band whensurrounded by said shell portion and portions of said shell opposite tosaid depressions formed to provide inwardly extending bosses disposed incontact with the concave surfaces of said depressions.

6. An electrical vacuum device comprising a bulb having a cylindricalneck portion, said neck portion having depressions formed in the surfacethereof, a retainer band surrounding said neck portion, said band havingindentations disposed in said depressions, a base for said device havinga cylindrical portion surrounding said retainer band and having aninside diameter slightly greater than the outside diameter of said bandwhen the band is disposed about said neck portion, perforate portionsdisposed over said indentations, the metal surrounding said perforationsbeing disposed in contact with the surfaces of said indentations.

DANIEL S. GUSTIN. ALFRED BONNEY, JR. CHRISTIAN FLEISCHMANN.

